I didn't think this made the beehaw stuff read only. I thought we got a snapshot from the moment they defederated, and it doesn't update after that. .world users can comment, but that's only on the snapshot that .world is storing. as time goes on it veers further and further from the 'real' content stored on beehaw.
famously small towns of Macon, GA (150k population) and Homestead, FL (80k population).
I live in a town of 5k, so I'm sure it's the same.